Instant Mytol

[archer]

As fortune would have it I finally succumbed to the Xtol hype and have been using it for months now and when I needed to develop some film from earlier this week, my Xtol was gone. The alternative was to mix some Mytol so while I was at it I thought I'd also mix some Instant Mytol, the formula, given here in the recipe forum. Both sets of negatives were beautiful and nearly identical, with a slight edge in softer contrast going to Instant Mytol but the difference is very subtle. Even with that said, I could not see any difference between these two sets of negatives and the negatives I've developed in Xtol. Is there anyone who has found the same thing? To be honest, I prefer to formulate my own processing chemicals, that way I'm never out of my preferred developer, fix,etc.
Denise Libby

 

[Gerald C Koch]

Mytol is not a very good formula for many reasons. It contains no chelating agent as Xtol does and so you may experience the dreaded sudden death syndrome. Look at Ryuji Suzuki's DS series of formulas for film in the APUG archives for much better Xtol equivalents.

 

[Jordan]

As fortune would have it I finally succumbed to the Xtol hype and have been using it for months now and when I needed to develop some film from earlier this week, my Xtol was gone. The alternative was to mix some Mytol so while I was at it I thought I'd also mix some Instant Mytol, the formula, given here in the recipe forum. Both sets of negatives were beautiful and nearly identical, with a slight edge in softer contrast going to Instant Mytol but the difference is very subtle. Even with that said, I could not see any difference between these two sets of negatives and the negatives I've developed in Xtol. Is there anyone who has found the same thing? To be honest, I prefer to formulate my own processing chemicals, that way I'm never out of my preferred developer, fix,etc.
Denise Libby

Instant Mytol was more of a chemistry experiment for me than anything else, and in coming up with it I was merely trying to simplify the recipe indicated for Mytol (which seemed cumbersome to me). Glad to hear that you got good results.

More comments from the original blog post on my website back in 2006: http://www.photosensitive.ca/wp/archives/50

I have never actually compared Instant Mytol head-to-head with XTOL, but in general you can tweak contrast by changing developing time.

Jerry is correct that neither Mytol nor Instant Mytol contain a chelating agent (though didn't the XTOL "sudden death" problems occur despite the presence of an EDTA-like chelating agent?) The advantage with Instant Mytol is that it can easily be mixed fresh right before use, and that is the only way I've ever used it.

 

[ntenny]

Does sulfite dissolve in TEA or glycol? If so, it seems like you could do a PC-TEA/PC-Glycol-type syrup, with the Instant Mytol proportions, and dilute it for one-shot use.

-NT

 

[Gerald C Koch]

The formula for Xtol was published in a Photo Techniques article by the two people who formulated it. It contained no chelating agent. Later Kodak added one which improved its stability. Sudden death is caused by the Fenton reaction which is catalysed by iron and coppr impurities in the water and also in the chemicals used to make Xtol. It can be very rapid causing the developer to lose activity in a few hours. The following developer contains two chelating agents salicylic acid and triethanolamine.

DS-10X Fine Grain Developer by Ryuji Suzuki

Dimezone S 0.15 g
Ascorbic acid 8.0 g
Boric acid 2.0 g
Salicylic acid 1.0 g
Sodium sulfite (anhydrous) 75 g
Triethanolamine 10.0 ml
Distilled water to male 1 l

Salicylic acid can be obtained from many pharmacies and is not expensive. All the other ingradients are available from companies that sell photo chemicals. Development times are comparable to those of Xtol. I have used this developer and it is very good producing results very similar to Xtol. Doubling the amount of boric acid will yield even finer gain. This version DS-10 requires a 20% increase in development times.

 

[Jordan]

Jerry, I would be surprised if that Photo Techniques article cited the exact formula for XTOL, which is probably a trade secret. It's been many years since I looked at that article, though. I'm sure it's a "pretty close" formula derived from examples in the patent literature.

I do note that Kodak's patent filings on XTOL-like developers, going back to 1996 at least, cite the use of a metal-chelating agent (DTPA) in all examples. Kodak could have included it in their applications but not in the actual product (again, trade secret), but they do describe the reasons for its inclusion, so I would be surprised if it wasn't in the commercial product from the start. They may have added others or changed the quantities after a while.

Salicylic acid is a good chelator for the iron impurities, because unlike EDTA or DTPA-type ligands, the complexes formed are not good oxidants. (Going from memory here based on the e-mail exchanges Ryuji and I had in 2005) so this is a good recipe when storage life matters. For mixing immediately before use, Instant MYTOL should be fine.

 

[Jordan]

Does sulfite dissolve in TEA or glycol? If so, it seems like you could do a PC-TEA/PC-Glycol-type syrup, with the Instant Mytol proportions, and dilute it for one-shot use.

Sodium sulfite does not dissolve appreciably in anything but water. You can mix the rest of the ingredients in a mixture of TEA and glycol, though. Have a look at the original formula page here on APUG: (there was a url link here which no longer exists)

(look at the text in italics just after the recipe -- the edit from December 2006)

 

[Gerald C Koch]

Jerry, I would be surprised if that Photo Techniques article cited the exact formula for XTOL, which is probably a trade secret. It's been many years since I looked at that article, though. I'm sure it's a "pretty close" formula derived from examples in the patent literature.

When I read the article I had the feeling that the published formula was what D and Z showed to Kodak management. Certainly changes could have been made later but it is unusal that they published a useful formula. In patent literature a critical part is usually left out so that the formula doesn't work. Anyway, if it looks like a duck ...

Kodak, Ilford, and Paterson all had problems with their ascorbate developers. As you mention common chelating agents like EDTA cause problems. I am not sure that Kodak was aware of the Fenton oxidation problem until the "sudden death" problem became wide spread.

How quickly the Fenton reaction destroys the ascorbate in a developer depends on the amount of iron present. It can be extremely rapid. Mixing a developer like instant Mytol for immediate use is probably OK but letting it sit over night might cause problems.